their grandparents in unionville, tennessee, when their home burned to the ground. they were presumed dead in the fire, but as the week went on, investigators digging through the ruins found the remains of the grandparents, but no sign of the children. >> they feel like they don't have solid evidence right now to assume that these children were in the fire. >> reporter: last night, the tennessee bureau of investigation went a step further and issued an amber alert saying in part, after an extensive five-day search, multiple fire experts have processed the scene and are unable to locate evidence that chloie and gage are victims of the fire." police say there are no persons of interest in the case. the fire marshall has no information on the cause of the fire. reached by phone last night, gage's father told the associated press "i don't know what to think" and repeated with his voice breaking "i don't know what to think." for "today," lori wilson, nbc news, new york. let's get a check of the day's top stories.